/Engine/Source/Editor/UnrealEd/Public/SkinWeightsUtilities.h
This function import a new set of skin weights for a specified LOD. Return true if the weights are successfully updates. If it return false, nothing in the skeletal skin weights was modified.
static bool ImportAlternateSkinWeight ( [USkeletalMesh](API\Runtime\Engine\Engine\USkeletalMesh) * SkeletalMesh, const [FString](API\Runtime\Core\Containers\FString) & Path, int32 TargetLODIndex, const [FName](API\Runtime\Core\UObject\FName) & ProfileName, const bool bIsReimport )